Getting started and basic introduction to Spring Boot

1. Getting started with Spring Boot

1. Introduction to Spring Boot

A framework to simplify Spring application development;

A big integration of the entire Spring technology stack;

One-stop solution for J2EE development;

2. Microservices

Microservices: architectural style (service microization)

An application should be a group of small services; it can communicate with each other via HTTP;

Single application: ALL IN ONE

Microservices: Each functional element is ultimately a software unit that can be independently replaced and independently upgraded;

Refer to the microservice documentation for details

3. Environmental preparation

Environmental constraints

--Jdk1.8: Spring Boot recommends jdk1.7 and above; java version "1.8.0_112"

-Maven3.x: maven 3.3 or above; Apache Maven 3.3.9

–IntelliJIDEA2017：IntelliJ IDEA 2017.2.2 x64、STS

–SpringBoot 1.5.9.RELEASE：1.5.9；

Unified environment

1. MAVEN settings;

Add to the profiles tag of the settings.xml configuration file of maven

<profile>
  <id>jdk-1.8</id>
  <activation>
    <activeByDefault>true</activeByDefault>
    <jdk>1.8</jdk>
  </activation>
  <properties>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
    <maven.compiler.compilerVersion>1.8</maven.compiler.compilerVersion>
  </properties>
</profile>

2. IDEA settings

Integrate maven in;

4、Spring Boot HelloWorld

One function:

The browser sends a hello request, the server accepts the request and processes it, and responds with the Hello World string;

1. Create a maven project

2. Import spring boot related dependencies

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.9.RELEASE</version>
    </parent>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
    </dependencies>

3. Write a main program; start the Spring Boot application

/**
 *  @SpringBootApplication 来标注一个主程序类，说明这是一个Spring Boot应用
 */
@SpringBootApplication
public class HelloWorldMainApplication {
    
    

    public static void main(String[] args) {
    
    

        // Spring应用启动起来
        SpringApplication.run(HelloWorldMainApplication.class,args);
    }
}

4. Write related Controller and Service

@Controller
public class HelloController {
    
    

    @ResponseBody
    @RequestMapping("/hello")
    public String hello(){
    
    
        return "Hello World!";
    }
}

5. Run the main program test

6. Simplify deployment

 <!-- 这个插件，可以将应用打包成一个可执行的jar包；-->
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

Mark this application into a jar package and execute it directly with the command of java -jar;